1. Field of the Invention
The present invention relates to a recording material, and more particularly, to a recording material having a coloring layer or having a coloring layer and a protecting layer, and having excellent water resistance, resistance to chemicals, running properties and manufacturing applicability.
2. Description of the Related Art
Pressure-sensitive paper, thermal-sensitive recording paper, photosensitive-pressure-sensitive paper, conduction-thermal recording paper, thermal transferring paper and the like are well-known as recording materials which use, as coloring components, a colorless electron donor dye and an electron acceptor compound (for details, see for example GB Patent No. 2,140,449, U.S. Pat. No. 4,480,052, U.S. Pat. No. 4,436,920, JP-B No. 60-23992, JP-A No. 57-179836, JP-A No. 60-123556, JP-A No. 60-123557 and the like). For example, thermal-sensitive recording papers using an electron donor dye precursor and an electron acceptor compound are disclosed in JP-B No. 45-14039, JP-B No. 43-4160 and the like. In addition, thermal-sensitive recording materials using a diazo compound are disclosed in JP-A No. 59-190886 and the like.
Further, thermal-sensitive recording materials having specific binders are disclosed in JP-A No. 1-288481, JP-B No. 6-88457, JP-A No. 1-272486 and JP-A No. 4-2-232091.
Recently, thermal-sensitive recording systems have been applied to many fields such as facsimiles, printers, labels, meter checking terminal apparatuses, devices for medical image output, prepaid cards and the like, and have a variety of uses. Accordingly, use of thermal-sensitive recording papers at home or outdoors has increased. In such cases, when a thermal-sensitive recording paper is handled with wet hands or the coated surface is made wet by rain or snow, adhesion or peeling of the thermal-sensitive paper may occur. Therefore, from a practical standpoint, there is an increasing need for recording papers to be water resistant.
Many attempts have been tried to eliminate the above drawback. In particular, the sticking of the recording paper and dregs greatly affect the running properties, and are believed to be caused by complicated factors such as the strength or glass transition point of the resin film used for the binder. However, no effective means have been proposed to solve this drawback. In addition, in order to improve the water resistance, there have been proposed a method using a cross-liking agent such as formalin, glyoxal or the like as a water resistance agent, and a method of cross-linking polyvinyl alcohol (PVA) by using a metallic chelating compound. However, since the drying-treatment temperature and the heat-treatment temperature are limited to relatively low temperatures in light of the properties of the coloring substance, the cross-linking is insufficient and, as a result, the water resistance of the recording paper is insufficient.